Conveyors

ABSTRACT

The invention is a variable speed conveyor which comprises a plurality of movable platforms, means to advance the platforms and means to guide the platforms around a circuit composed of a forward path, a revolving zone at one extremity of travel of the conveyor, a return path and a revolving zone at the other extremity of travel of the conveyor, wherein, in operation, the platforms in each revolving zone revolve about an axis substantially perpendicular to the plane in which the platforms move whereby the platforms are available for conveying on both the forward and the return path and wherein the platforms are supported by wheels which run on tracks, the distance between the tracks varying as the speed of the conveyor varies. An endless chain provided with guide rollers for sliding movement along guide channels in the undersides of the platforms is disclosed for driving the platforms through the revolving zone.

United States Patent 11 1 Kondo et a1.

[ CONVEYORS [75] Inventors: Kyozo Kondo, Mihara; Takeyoshi Okimoto,Takehara, both of Japan [73] Assignee: Mitsubishi Jukogyo KabushikiKaisha, Tokyo, Japan [22] Filed: Mar. 28, 1974 [21] Appl. No.: 455,807

[30] Foreign Application Priority Data 1111 3,874,297 1 Apr. 1,1975

Primary Exan11'nerLloyd L. King Assistant Examiner-D. W. Keen Attorney,Agent, or Firm-Cushman, Darby & Cushman [5 7] ABSTRACT The invention isa variable speed conveyor which comprises a plurality of movableplatforms, means to advance the platforms and means to guide theplatforms around a circuit composed of a forward path, a revolving zoneat one extremity of travel of the conveyor, a return path and arevolving zone at the other extremity of travel of the conveyor,wherein, in operation, the platforms in each revolving zone revolveabout an axis substantially perpendicular to the plane in which theplatforms move whereby the platforms are available for conveying on boththe forward and the return path and wherein the platforms are supportedby wheels which run on tracks, the distance between the tracks varyingas the speed of the conveyor varies. An endless chain provided withguide rollers for sliding movement along guide channels in theundersides of the platforms is disclosed for driving the platformsthrough the revolving zone.

3 Claims, 13 Drawing Figures as a9 1Q m m a Q -4 PATENTED APR 1 i975 saw3 u; 7

PATENTED APR 7 I975 SHIT t [If 7 coisvrzvoks FIELD OF THE INVENTION Thisinvention relates to variable speed conveyors.

BACKGROUND OF THE INVENTION Among the conventional transport systemsgenerally called "moving footway. there is a system constructed bylaying horizontally an escalator" and a system of belt-conveyor type onwhich passengers can ride. However. these prior art systems havedisadvantages in that they are of fixed-speed and. in order to assuresafety by mitigating the shock when a pedestrian mounts the system. themoving speed of the system was limited to a very low speed.

As an improved system free from the aforementioned disadvantages. avariable speed conveyor has been developed. constructed in such mannerthat respective platforms which are capable of moving along theirwidth-wise direction or along a direction transverse to their widthwisedirection. are displaced in their lengthwise direction with respect toeach other. the displacement being zero or small in a low speed zone.and large in a high speed zone. In this conveyor system. however. theplatforms are adapted to be reversed from their forward path to theirreturn path by revolving about a horizontal axis extending in thewidthwise direction of the conveyor system. similar to the prior artsystems. Thus only the platforms on their forward path. located on theupper path of the conveyor. are used for transportation. while theplatforms on their return path. located on the lower path of theconveyor, cannot contribute to transportation at all. Therefore. thetransport efficiency of this conveyor system was low.

SUMMARY OF THE INVENTION According to the present invention there isprovided a variable speed conveyor which comprises a plurality ofmovable platforms, means to advance the platforms and means to guide theplatforms around a circuit composed of a forward path. a revolving zoneat one extremity of travel of the conveyor. a return path and arevolving zone at the other extremity of travel of the conveyor.wherein. in operation. the platforms in each revolving zone revolveabout an axis substantially perpendicular to the plane in which theplatforms move whereby the platforms are available for conveying on boththe forward and the return path and wherein the platforms are supportedby wheels which run on tracks. the distance between the tracks varyingas the speed of the conveyor varies.

The invention includes means for advancing the platforms along thecurved track portion which proceeds through the revolving zone. Thisadvancing means includes cable means. endless chain means or the like.

movement about a generally horizontal path including a run whichunderlies the platforms when the platforms are on said curved portion ofthe track means. said run gradually cutting inwardly more deeplycrosswise of said curved portion. then proceeding generally parallel tothe curved portion, and then gradually cutting outwardly more deeplycrosswise of said curved portion;

a plurality ofdrive elements mounted on the endless chain means atequally spaced intervals corresponding locations of the individual onesof said (ill platforms. as the platforms are on said curved portion ofthe track means:

and progressive engagement surface means on each platform. eachelongated in a generally horizontal plane widthwise of the respectiveplatform. the respective progressive engagement surface means beingarranged to be engaged by the respective drive elements mounted on theendless chain means. whereby the platforms are driven along said curvedportion of the track means at least in part by the respective driveelements entering into driving engagement with the respective engagementsurface means from outwardly of the respective platforms progressigninwardly and then outwardly therealong and then retreating from drivingengagement therewith.

In the embodiment illustrated. the drive elements are rollers mounted atequally spaced intervals along the chain means and the progressiveengagement surface means on the platforms are guide channel means movingoutwardly directed openings for receiving and discharging the rollermeans.

In one form the invention provides a conveyor constructed in such mannerthat respective platforms which are capable of moving either along theirwidthwise direction or along a direction transverse of the widtbwisedirection. are displaced in their lengthwise direction with respect toeach other. the displacement being zero or small in a low speed zone andlarge in a high speed zone. characterized in that the platforms arerevolved about an axis perpendicular to a plane of movement of theplatforms rather than being reversed about an axis parallel to the planeof movement of the platforms.

It is possible to allow a large number of passengers to successively andsafely get on and/or get off the conveyor system in the low speed zone.and also to transport the passengers at a high speed in the high speedzone which occupies the most part of the transport interval.

Since the platforms are adapted to be revolved about an axisperpendicular to the plane of movement of the platforms rather than tobe reversed by revolving about an axis parallel to the plane of movementof the platforms. not only the forward path of the conveyor but also thereturn path can be used for transportation of passengers. Consequentlythe transport capacity efficiency can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is further illustratedby reference to the accompanying drawings showing. by way of example. anembodiment of the conveyor in accordance with the invention. in which:

FIG. 1 is a schematic plan view showing an outline of a conveyoraccording to the present invention;

FIG. 2 is a plan view of the same embodiment;

FIG. 3 is a plan view showing low speed zones and a revolving zone ofthe same embodiment;

FIG. 4 is an enlarged partial plan view showing platforms in a highspeed zone and in a low speed zone with overlapped representation forthe same embodiment:

FIGS. 5 and 6 are transverse and longitudinal crosssection views takenalong lines VV and VIVI. respectively. in FIG. 4;

FIG. 7 is a side view related to FIG. 6'.

FIG. 8 is a view taken along line VII-VII in FIG. 6 as viewed in thedirection of arrows;

FIG. 9 is an enlarged partial plan view of the portion IX in FIG. 3;

HG. I is an enlarged partial side view in the direction of arrow X inFIG. 9:

FIG. I I is an enlarged cross-section view taken along line Xl-Xl inFIG. 3'.

FIG. I2 is a cross-section view taken along line Xll- Xll in FIG. 4'.and

FIG. I3 is a plan view for the portion shown in FIG. 12.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS Referencenumeral I designates a platform formed in a substantially rectangularshape, and at the opposite ends in the lengthwise direction of theplatform I are integrally provided additional spaces 2 for mountinghandrails. Reference numerals 3 and 4 designate a return path high speedzone and a forward path high speed zone. respectively. To the downstreamend of the return path high speed zone 3 an exit low speed zone 6 isconnected via a deceleration zone 5. Further downstream of the exit lowspeed zone 6 an entrance low speed zone 8 is connected via a revolvingzone 7. The downstream end of the entrance low speed zone 8 is connectedvia an acceleration zone 9 to the forward path high speed zone 4.Between the downstream end ofthe forward path high speed zone 4 and theupstream end of the return path high speed zone 3 are also provided adeceleration zone 5. an exit low speed zone 6. a revolving zone 7. anentrance low speed zone 8 and an acceleration zone 9 (not shown in thedrawings) which are constructed similarly to those described above. Inaddition, the entrance low speed zone 8 and the exit low speed zone 6are provided with amounting station A and a dismounting station 8.respectively.

Except in the revolving zone 7. over the entire zones 3. 4. 5. 6, 8 and9, the platforms I are adapted to be slidably displaceahle in theirlengthwise direction with respect to each other. while their oppositeside edges directed in their lengthwise direction are maintained inclose contact to each other, as will be fully described later and asshown in FIG. I2.

As shown in FIG. 2. an outer track 10 and an inner track I I aredisposed on a floor extending in the direction in which it is intendedto move the platforms. Wheels I2 and I3 which can roll within the outertrack III and inner track I] are pivot-ably mounted on the lower surfaceof the platform I as shown in detail in FIG. 5.

As will be apparent from FIGS. I and 2, the distance between the outertrack III and the inner track II is wide in the low speed zones 6 and 8,is narrow in the high speed zones 3 and 4 and is continuously varied inthe acceleration and deceleration zones 9 and 5, respectively.Consequently in the low speed zones 6 and 8. when the platforms I aredriven along their widthwise direction the aforementioned displacementin the lengthwise direction is zero. In the high speed zones 3 and 4.when the platforms I are driven along a direc tion transverse of thewidthwise direction the afore mentioned displacement in the lengthwisedirection is a maximum. In the acceleration and deceleration zones 9 and5. respectively, the direction of movement ofthe platforms with respectto their widthwise direction is continuously varied while theaforementioned displace ment in the lengthwise direction alsocontinuously varies.

As shown in FIG. 3. outside the low speed zones 6 and 8. a low speedzone outside driving chain 14 extends around a chain driving sprocketI5. Meshing pawls 16 are fixedly secured to the driving chain 14 at apitch equal to the pitch of the platforms 1. so that pins 17 mounted onthe platforms I and projecting therefrom engage the meshing pawls I6.

In addition. as partly shown in FIG. 3 inside the low speed zones 6 and8 there is a low speed zone inside driving chain I8 which extends arounda large chain driving sprocket 20 which rotates about its shaft I9.Meshing pawls 2I are also fixedly secured to the driving chain I8 at apitch equal to the pitch of the platforms. so that pins 22 projectingfrom the platforms engage the meshing pawls 21.

Since the low speed zone outside and inside driving chains I4 and I8 areadapted to be driven by the sprockets I5 and 20, respectively, at thesame fixed speed. within the low speed zones 6 and 8 the platforms I areconveyed at a fixed speed and a mutually equal pitch is maintained whilethe platforms 1 are perpendicular to the direction of movement.

Inside the revolving zone 7, a guide member 23 is provided along anouter circumference of the chain driving large sprocket 20. whileoutside the revolving zone 7. a semi-circular guide member 24 isprovided extending to the outer end edges of the platforms 1 in the lowspeed zones 6 and 8.

Further in the revolving zone 7, a chain 25 extends around a fixed-speeddriving sprocket 26 and sprockets 27. On the chain 25 are mounted aplurality of rollers 28 at equal intervals. Guide channels 29 {sec FIGS.9 and [0) are provided on the lower surfaces of the platforms I with therollers 28.

The speed of the chain 25 is preselected relatively high so that thespeed component of the chain 25 along the direction of movement of theplatforms I in the low speed zone 6 at the point where the roller 28begins to engage with the guide channel 29 may be equal to the speed ofmovement ofthe platforms I in the low speed zone 6. The interval betweenthe rollers 28 is preselected so that in the middle portion of therevolving zone 7. the lengthwise directions of the platforms I isdirected towards the shaft 19 of the large sprocket 20. Therefore. theplatforms I in the exit low speed zone 6 can be smoothly passed into therevolving zone 7, where the outside end of each platform is accelerateduntil it reaches the middle portion and then it is decelerated. Thus.the platforms I are adapted to be revolved by I about the shaft I9 ofthe large sprocket 20 and guided by the guide members 23 and 24.

Explaining now the details of the platforms I as illustrated in FIG. 4.reference numeral 30 designates a step board of the platform I. and twoparallel lines C-C represent the opposite side edges of the conveyorconsisting of an array of platforms I in the high speed zones 3 and 4.In addition, in the same Figure is shown a chain line DD whichrepresents the direction of movement of the platforms I in the low speedzones 6 and 8. It is to be noted that FIG. 4 shows the track and wheelarrangements both in the high speed zone and in the low speed zoneoverlapped in the same Figure.

More particularly. in the high speed zones 3 and 4 a pair of outertracks 10:- for high speed zones and a pair of inner tracks I It forhigh speed zones are laid parallel to the opposite side edges C-C of theconveyor (only the right side ones of the pairs being shown in theFigure). In the low speed zones 6 and 8 a pair of outer tracks IOu' forlow speed zones and a pair of inner tracks lid for low speed zones arelaid parallel to the direction of movement DD of the platforms I. thatis. the widthwise direction of the platforms (only the left side ones ofthe pairs being shown in the Figure). In the high speed zone and in thelow speed zone. respectively. the outer track pair 101' or HM and theinner track pair Ilc or IId are engaged with wheels on the opposite.sides 12c. 12d and I3('. I3u'.

In addition, on the handrail mounting spaces 2 of the platform I aremounted handrails 3I which are bent in a L-shape, and the handrails ofthe platforms I adjacent to the platform I depicted by a solid line inthe high speed zones 3 and 4. are depiced by a double-dot chain line andgiven the reference numeral 3h.

Still further. as shown in FIGS. 4 and 6. in the high speed zones 3 and4 is provided a chain 32 along a line EE (in FIG. 4) parallel to theouter and inner tracks c and [01]. Two protrusions 33 to engage thechain 32 are mounted on the lower surface of the platform I. Assumingthat the distance between the two protrusions 33 is represented by l.the distance from a cross point F where the chain 32 intersects with thelonger edge ofthe platform I to the nearest one of said protrusions 33is preselected to be equal to V2, and therefore. the distance betweenthe protrusions 33 on the same platform I is equal to the distancebetween the adjacent protrusions 33 on the adjoining platforms I.

As shown in FIG. 5. each of the wheel assemblies I and I31 to engage theouter and inner tracks Illc and l lr'. respectively. in the high speedzones 3 and 4. consists of a support member 34. a rotary shaft 36rotatably fitted in a bearing bush of the platform I. a thrust ballbearing 37 for allowing the rotary shaft 36 to rotate lightly. an innerrace 38 fitted to the support member 34. balls 3) arranged around theouter circumference of the inner race 38. an outer race 40 fitted aroundthe outer periphery ofthe balls 39. and an outer ring of rubber 4|fitted around the outer circumference of the outer race 40.

As shown in FIGS. 6 and 8. on a mutual coupling shaft 42 of a chain 32is rotatably supported a roller 43. and lock pieces 45 adapted to graspa tip end outer buffer piece 44 of the protrusion 33 are integrallymounted on the chain 32 with rivets 46. A sprocket 47 for driving thechain 32 is provided with notches 48 and shown in FIG. 7 so that thesprocket 47 will not make contact with said protrusion 33 and lockpieces 45.

The details of the portion of the platform I which makes contact withthe guide member 23 or 24 in the revolving zone 7. are shown in FIG. II. The pin I7 provided at the opposite ends of the platform I. isrotatably fitted via a bearing bush 50 around a shaft 49 projectingdownwardly from the platform I. and prevented from falling down by meansof a cap 51. Above the pin I7 is rotatably fitted a guide roller 54 viaa bearing bush 53 separated from the pin I7 by means of a spacer S2. Theguide roller 54 is adapted to roll along said guide member 23 or 24 inclose contact therewith. Reference numeral 55 designates the centre ofthe low speed zone outside and inside driving chains 18 and 14,respectivelv.

A transverse cross-section of the platforms I is shown in FIG. 12. Alongone side edge of the platform l is keyed a slide piece 56 ofsubstantially cylindrical shape which is integrally secured to theplatform I by means of bolts 58. On the top of the slide piece 56 areprovided comb-like ridges 59 directed laterally (parallel to the planeofthe paper in FIG. I2). Except for in the revolving zone 7. over theentire zones 3. 4. S. 6. 8 and 9 the slide piece 56 can relatively slidealong the opposite side edge in the lengthwise direction of theadjoining platform I while keeping tight contact with the opposite sideedge. and also the platforms I can tilt relative to each other about thecentre axis (directed at a right angle to the plane of the paper in FIG.l2) of the slide piece 56.

In addition. on the step board 30 of the platform I are providedstrip-like ridges 60 directed in the widthwise direction of the platformI (see FIG. [3). and scrapers 61 disposed in the exit or entrance lowspeed zone 6 or 8 are adapted to properly and loosely lit in the groovesbetween the ridges 59 and 60. On the lower surface of the platform I areprovided bores 62 for mounting the bolts 58.

Since the illustrated embodiments is constructed as described above.when the driving sprocket 47 (see FIG. 7) in the high speed zones 3 and4. the driving sprockets [5 (see FIG. 3) in the low speed zones 6 and 8.and the driving sprockets 20 and 26 (see FIG. 3) in the revolving zone 7are rotated. the chains 32. I4. I8 and 25 are driven simultaneously.

As shown in FIG. 4. in the high speed zones 3 and 4, during a period inwhich the platform I moves up to the position where the adjacentplatform I was initially located. the platform I moves along the outerand inner tracks Hit and lit for a distance about twice as long as thewidth of the platform I. because the platforms I are tilted by about 30with respect to the outer track Illc and the inner track He, and thusthe passengers are conveyed at a speed about twice as high as the movingspeed in the low speed zones 6 and 8.

In the deceleration zone 5 or the acceleration zone 9. the platforms Iare subjected to a pressing force from the platforms I in the backwardpath high speed zone 3 or the entrance low speed zone 8 on the upstreamside which are driven by the chains 32. I4 and I8. and also they aresubjected to restriction by the outer and inner tracks 10 and I I. sothat the platforms I in the deceleration or acceleration zone 5 or 9 aremoved while being decelerated or accelerated and varying the relativedisplacement in the lengthwise direction as shown in FIG. 2.

In the exit low speed zone 6 and the entrance high speed zone 8. theplatforms I are moved at a low speed along their widthwise directionwhile their relative displacement in the lengthwise direction ismaintained at zero.

In the revolving zone 7. the interval between the outer ends of theadjacent platforms 1 is progressively widened and after passing themiddle portion it is progressively narrowed by the action of the rollers28 on the chain 25 which are engaged with the guide channels 29 on thelower surfaces of the platforms I. while the interval between the innerends of the adjacent platforms I is kept constant by the meshing pawls21 of the low speed zone inside driving chain 18. and thus the platformsI are revolved by l along a semicircle having its centre at the shaft 19while their inner and outer ends are guided by the guide members 23 and24. respectively.

As described. since the platforms I are revolved along a horizontalplane about a vertical axis in the revolving zone 7. not only theforward path but also the backward path can be used for transporation ofpassengers. so that the transport capacity is doubled in comparison tothe prior art conveyor in which only the forward path can be used, andthus the transport efficiency is widely enhanced.

In addition. in the high speed zones 3 and 4. the low speed zones 6 and8. and the revolving zone 7. since the interval between the adjacentplatforms 1 is restricted by the meshing with the chains 32. l4. l8 and25. the slide piece 56 along one side edge of the platform 1 and theopposite side edge of the adjacent platform I can slide relative to eachother while being kept in tight contact with each other without a gap orspace appearing therebetween and without causing disengagementtherebctween.

Furthermore, since the adjoining platforms I can be tilted relative toeach other about the centre axis of the slide piece 56. the conveyor canbe tilted relative to the horizontal plane without requiring anyspecific coupling means.

While the present invention has been described above with reference to apreferered ambodiment, it is intended that the present invention shouldnot be limited to the illustrated embodiment but various changes indesign could be made without departing from the scope of the invention.

We claim:

l. A variable speed conveyor which comprises a plurality of movableplatforms, means to advance the platforms and means to guide theplatforms around a cir' cuit composed of a forward path, a revolvingzone at one extremity of travel of the conveyor. a return path and arevolving zone at the other extremity of travel of the conveyor.wherein. in operation the platforms in each revolving zone revolve aboutan axis substantially perpendicular to the plane in which the platformsmove whereby the platforms are available for conveying on both theforward and the return path and wherein there is provided in eachrevolving zone means to engage the outermost end of each platform andadvance the platform through the revolving zone.

comprising a cable on which rollers are situated at equally spacedintervals and wherein the platforms are provided with slots which areengaged by the rollers in the revolving zone.

2. In a variable speed conveyor which includes a plu rality of platformsrollingly mounted in a series upon a circuit of generally horizontaltrack means which includes at least one portion which is curved in agenerally horizontal plane and means for advancing the platforms alongthe track means.

the improvement wherein:

the advancing means includes means for advancing the platforms throughsaid curved portion. comprising: endless chain means mounted on sprocketmeans for movement about a generally horizontal path including a runwhich underlies the platforms when the platforms are on said curvedportion of the track means. said run gradually cutting inwardly moredeeply crosswise of said curved portion, then proceeding generallyparallel to the curved portion. and then gradually cutting outwardlymore deeply crosswise of said curved portion; a plurality of driveelements mounted on the endless chain means at equally spaced intervalscorresponding to locations of the individual ones of said platforms. asthe platforms are on said curved portion of the track means; andprogressive engagement surface means on each platform each elongated ina generally horizontal plane widthwise of the respective platform. therespective progressive engagement surface means being arranged to beengaged by the respective drive elements mounted on the endless chainmeans. whereby the platforms are driven along said curved portion of thetrack means at least in part by the respective drive elements enteringinto driving engagement with the respective progressive engagementsurface means from outwardly of the respective platforms progressinginwardly and then outwardly therealong and then retreating from drivingengagement therewith.

3. The variable speed conveyor improvement of claim 2. wherein the driveelements on the endless chain means are constituted by rollers andwherein the progressive engagement surface means on each platform isconstituted by guide channel means thereon. having an outwardly directedopening for receiving and discharging the respective roller means.

1. A variable speed conveyor which comprises a plurality of movableplatforms, means to advance the platforms and means to guide theplatforms around a circuit composed of a forward path, a revolving zoneat one extremity of travel of the conveyor, a return path and arevolving zone at the other extremity of travel of the conveyor,wherein, in operation the platforms in each revolving zone revolve aboutan axis substantially perpendicular to the plane in which the platformsmove whereby the platforms are available for conveying on both theforward and the return path and wherein there is provided in eachrevolving zone means to engage the outermost end of each platform andadvance the platform through the revolving zone, comprising a cable onwhich rollers are situated at equally spaced intervals and wherein theplatforms are provided with slots which are engaged by the rollers inthe revolving zone.
 2. In a variable speed conveyor which includes aplurality of platforms rollingly mounted in a series upon a circuit ofgenerally horizontal track means which includes at least one portionwhich is curved in a generally horizontal plane and means for advancingthe platforms along the track means, the improvement wherein: theadvancing means includes means for advancing the platforms through saidcurved portion, comprising: endless chain means mounted on sprocketmeans for movement about a generally horizontal path including a runwhich underlies the platforms when the platforms are on said curvedportion of the track means, said run gradually cutting inwardly moredeeply crosswise of said curved portion, then proceeding generallyparallel to the curved portion, and then gradually cutting outwardlymore deeply crosswise of said curved portion; a plurality of driveelements mounted on the endless chain means at equally spaced intervalscorresponding to locations of the individual ones of said platforms, asthe platforms are on said curved portion of the track means; andprogressive engagement surface means on each platform each elongated ina generally horizontal plane widthwise of the respective platform, therespective progressive engagement surface means being arranged to beengaged by the respective drive elements mounted on the endless chainmeans, whereby the platforms are driven along said curved portion of thetrack means at least in part by the respective drive elements enteringinto driving engagement with the respective progressive engagementsurface means from outwardly of the respective platforms progressinginwardly and then outwardly therealong and then retreating from drivingengagement therewith.
 3. The variable speed conveyor improvement ofclaim 2, wherein the drive elements on the endless chain means areconstituted by rollers and wherein the progressive engagement surfacemeans on each platform is constituted by guide channel means thereon,having an outwardly directed opening for receiving and discharging therespective roller means.